1. Field of the Invention
The present invention relates to a thermal image transfer recording medium, in particular, a thermal image transfer recording medium for clothing items, and to a recording method by using the thermal image transfer recording medium.
2. Discussion of Background
Thermal image transfer recording media for clothing items are used for thermally recording information about the handling of clothing items on image receiving materials such as labels or the like.
Since such thermal image receiving materials are used by being attached on clothing items by sewing, it is required that images formed on the image receiving materials be neither washed off nor peeled off during washing and ironing.
Many thermal image transfer recording media for clothing items have been proposed. In particular, varieties of resins for use in a thermal image transfer ink layer of such thermal image transfer recording media have been investigated for the purpose of developing such an ink layer that is not peeled off the image receiving material during the course of laundering, when the ink layer is thermally transferred imagewise to the image receiving material.
As one kind of such resins, cellulose derivatives are conventionally known as resins to be contained in a thermal image transfer ink layer.
Por instance, Japanese Laid-Open Patent Application 47-11215 discloses a thermal image transfer ink composition comprising a cellulose derivative, a thermoplastic resin, a plasticizer and a sensitizer, which is coated in the form of an ink layer on a base material; Japanese Laid-Open Patent Application 63-34182 discloses a thermal image transfer ink layer which comprises a thermofusible material and a cellulose-based resin; Japanese Laid-Open Patent Application 1-133784 discloses a thermal image transfer ink layer which comprises a resin and at least one component selected from the group consisting of a cellulose fatty acid ester, vinyl chloride and vinylidene chloride; Japanese Laid-Open Patent Application 2-229072 discloses a thermal image transfer ink layer which comprises polyamide resin, nitrocellulose resin, carnauba wax, and a coloring pigment; and Japanese Laid-Open Patent Application 3-192170 discloses an ink layer composition for coating, which comprises a coloring agent, a binder comprising ethyl cellulose, a thickening agent and a solvent.
Images formed by the above-mentioned thermal image transfer ink layers comprise ink components which are soluble in cleaning solvents such as water, warm water, 1,1,1-trichloroethane, perchlene and naphtha, so that such images do not have sufficiently high laundering resistance for use in practice.
Under such circumstances, the inventors of the present invention have previously proposed in Japanese Patent Application 05-60984 a thermal image transfer recording medium which comprises a support, and a release layer comprising a wax component, an undercoat layer comprising a resin component, and a thermal image transfer ink layer which are successively overlaid on the support, wherein at least one of the undercoat layer or the ink layer comprises a cellulose derivative as a binder resin, whereby not only the laundering resistance of images formed on an image receiving material, but also the thermosensitivity of the thermal image transfer recording medium at thermal image transfer recording can be improved.
However, when thermally transferred images are formed on varieties of image receiving materials, for example, films such as polyethylene film, polypropylene film, polyester film, acetate film and nylon film, cloth, and paper, by use of the above-mentioned thermal image transfer recording medium, not all the image receiving materials exhibit excellent adhesiveness to the thermally transferred images from the thermal image transfer recording medium, and as a matter of course, the anti-friction performance of the thermally transferred images (i.e. the performance that thermally transferred images are not peeled off the image receiving material when the thermal transferred images are frictioned) is insufficient for use in practice. Furthermore, the heat resistance of the images which are thermally transferred to such image receiving materials is also insufficient for use in practice.